Cap for insulated electrical connector



April 12, 1960 E. s. RAM Em 2,932,685

CAP FOR INSULATED ELECTRICAL CONNECTOR Filed Dec. 4. 1958 Ul HH F|G.2 FIG. 3

INvENro-Rs Edward S. Railo BY William S. Chickvory ATTORNEY United States Patent O Edward S. Raila and William S. Chiekvary, Norwalk,

Conn., assignors to Burndy Corporation, a corporation of New York Application December 4, 1958, Serial No. 778,110 6 Claims. (Cl. 174-84) Our invention relates toelectrical connectors having tubular malleable metal bodies having coaxially disposed insulating sleeves and, more particularly, to electrical connectors of the type in which the tubular body is indented or crimped to the wire through the insulating material.

In the copending application of cci-inventor William S. Chickvary, Serial 737,142 filed May 22, 1958, there is disclosed an electrical connector having a tubular Inalleable body disposed in an insulating sleeve made of material capable of substantially transmitting the forces necessary for crimping the metal body to an inserted conductor. Oxide inhibiting compound is disposed within the tubular body and end caps are provided to prevent the loss of the compound during installation of the connector. Each of the end caps is provided with a weakened central section through which the bared conductors may be inserted to have the tubular metallic body crimped thereto.

The caps are composed of a material which is resilient and has elastic memory so that the caps will grip and form a water repellant seal about the inserted conductor and contain the oxide inhibiting compound within the tubular connector. The resilient and elastic memory characteristics of the caps tend to restrain the conductor from pulling out of the connector until the installation is completed.

While this prior art device has proved satisfactory, we have found that the end cap can be improved if means are provided to predetermine the manner in which the end cap will behave when pierced by the conductor and, moreover, the end cap will be improved further 4by providing means to assist in forming the water repellant seal after the conductor pierces the end cap.

One of the objects of our invention, therefore, is to provide an end cap for a preeinsulated electrical connector which includes means for predetermining how the connector cap will break when a conductor is inserted through its weakened section.

Another object of this invention is to provide means to assist in forming a water repellant seal around a piercing conductor.

One of the features of our invention is the provision of an end cap composed of insulating material which is resilient and has an elastic memory. The end cap includes a weakened central section through which a bared conductor may be inserted into the electrical connector. This weakened central section includes a reinforcing rib or spoke which functions as a hinge when the weakened central section is pierced.

Another feature of the end cap of our invention includes a sealing bead formed of the end cap resilient material which acts as a reinforcement, exerting pressure on the cable insulation to form a seal around the conductor when the conductor pierces the weakened central section.

These and other features of this invention will become more apparent by reference to the following description 2,932,685 Patented Apr. 12, 1860 ,ICC

taken in conjunction with the accompanying drawings in which:

Fig. 1 is a cross sectional view of an electrical connection utilizing the end cap of our invention;

Fig. 2 is a bottom view of the end cap of our invention; and

Fig. 3 is a cross sectional view taken along the planes 3-3 of Fig. 2.

In the drawings, reference numeral 10 designates a tubuiar body or sleeve composed of a malleable metal such as aluminum or copper. The diameter of the internal bore of the sleeve is suicient to permit the bared conductor 12 to be inserted therein. A cable st-op 14 may be formed in the bore of the sleeve 10` to prevent the overinsertion of the cable. A tube 16 composed of insulating material is disposed in coaxial relation to the metal sleeve 10. The insulating sleeve 16 may be made of any well known material such as nylon, copolymers of vinyl chloride-vinyl acetate or saran, any of which is capable of withstanding the compression forces of indenting as hereinafter explained.

An oxide inhibiting compound 22 is disposed within the bores of the metal sleeve 10 and end caps 24 and 26 are utilized to retain the compound therein. The end caps may be friction fitted to the outer portion of the insulating sleeve 16. Other means such as cement may be utilized to retain the caps on the insulating sleeve.

As shown in Figs. 2 and 3, the end cap 24 has a central weakened section 30 composed of thinner material than the remainder of the cap. The weakened section 30 is tapered from the central point 31 where it is approximately as thick as the remainder of the cap to its thinnest section where it joins the remainder of the cap. Extending radially from the center of the weakened section to the point where it joins the remainder of the cap is a spoke 32 or radial area which is thicker than the remaining portion of the central weakened section 3u.

`Circumferentially surrounding the central weakened section is a bead 34 which functions as a reinforcement to cause the periphery of the pierced section of the cap to encase the cable insulation and function as a water repellant seal when a conductor pierces the weakened section.

In use, an insulated wire has its conductor portion 12 bared and inserted through the weakened central portion 30 of the end cap 24. As the weakened central section 30 of the end cap 24 is pierced, the spoke 32 tends to function as a hinge, since it has a greater resistance to tear than the remainder of the weakened periphery.

The end cap 24 is preferably made of a material which has an elastic memory so that it tends to tightly grip the insulation 38 of the conductor. The conductor is retained within the sleeve 10 due to this gripping action of the end cap. To assist in forming a water repellant seal, the sealing bead 32 may be molded into the cap. This bead 32 acts as a reinforcement to form a seal preventing the entrance of drops of moisture; thus preventing corrosion of the conductor and connector. This action is aided and abetted by the extrusion of the oxide inhibiting compound 22 around the wire to iill the spaces in the bore. After the conductor is disposed in the bore of the sleeve 10, indentations or crimps 44 are made by suitable tools through the insulating sleeve 16 to join the metal sleeve 10 to the conductor 12. Naturally, the insulation must have the physical characteristic of being capable of withstanding the indentation without substantial deleterious effects and, moreover, must have the physical characteristics of being capable of transmitting the indenting forces from the tool to the sleeve 10 to pressure forge the connector and conductor.

We have thus described our invention, but we desire it understood that it is not confined to the particular aasaese.

forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other Ways Without departing from the spirit of our invention and, therefore, We claim broadly the right Yto employ all equivalent instrumentalities coming within the scope ofthe appended claims, and by means of which, objects of our invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown are only some of the many thatV ca n be employed to attain these objects and accomplish these results.

We claim:

1. In an electrical connector having a malleable metal sleeve, an insulating cover coaxial therewith and having ends thereof extending beyond the ends of said sleeve; end closures for said insulating cover each comprising an insulating cap having the cylindrical side thereof adapted to be friction tted to said insulating cover and the end thereof having a central section having a weakened perimeter and a radial reinforcement for said central section extending across said weakened perimeter.

2. An end cap according to claim l which further includes a reinforcing bead integral With said end section circumferentially encompassing said central section weakened perimeter.

3. An end cap according to claim 2 composed of a resilient plastic material having an elastic memory.

4. A plastic end cap for sealing an insulated electrical connector comprising a cylindrical cap having an end section composed of a resilient material having an elastic memory, said end section including a central portion having a perimeter with a thickness less than the thickness of the remainder of said end cap, the thickness of said central portion tapering from a minimum at its periphery to a maximum at the center of said end section, said perimeter further including a section having a greater thickness than the remainder of said perimeter.

5. An end cap according to claim 4 which further includes a reinforcing bead circumferentially enclosing said central portion.

6. An electrical connection comprising a malleable metal sleevee, an insulating cover coaxial therewith and having ends thereof extending beyond the ends of said sleeve and end closures to sealthe ends of said cover, conductors disposed through openings pierced in said end closures and having said insulating cover and malleable sleeve crimped thereto, said end closures each including a reinforcing bead surrounding said opening through which said conductor is disposed and a section of said end cover hinged about said opening and extending into said malleable metal sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 2,234,640 Austin Mar. 1l, 1941 2,316,267 McLarn Apr. 13, 1943 2,429,585 Rogoi Oct. 21, 1947 OTHER REFERENCES Publication I: Crimpit Bulletin C11-57, published by Burndy Corporation, August 1957, Norwalk, Conn. (pages 12 and 13 relied on).

Publication 1I: Recent Developments in the Use of Polythene Cables for Subscribers Lines (Vi/addon) published in The Post Oice Electrical Engineering Journal, vol. 50, No. 4, January 1958 (page 219 relied on).

UNITED STATES PATENT oFF-ICE CERTIFICATION OF CORRECTION Pai-ent No. 932,685 April 12, 1960 Edward S. Raila et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, lines lo through I8, for "and a section of said end cover hinged about said opening and extending into said malleable metal sleeve., read eand a section of said end Cover hinged about seid opening and extending into said insulating cover.. me.,

Signed and sealed this 2nd day of May l9l (SEAL) Attest:

ERNEST W SWIDER DAVID L LADD Aesing Officer Commissioner of Patents nNTTnn STATES PATENT OFFICE CE 'llllCATlDN 0F CRRECTIN Patent No. 2Y932q685 Aprii 12q 196e Edward S. Raila et al.,

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected belowa Column 4, lines l through 18, for "and a sect-ion of said end cover hinged about said opening and extending into said malleable metal sleeved" read and a section of said end cover hinged about said opening and extending into said insulating cox/en,

Signed and sealed this 2nd day of May l96l (SEAL) Attest:

ERNEST W SWIDER DAVID L LADD Aee'zng @fioer Commissioner of Patents 

